Antenna selection and application FAQ

Q: 1. Why are all the onboard antennas we see serpentine?

A: Many Wi-Fi module, Bluetooth module antennas etc., use serpentine antenna onboard, which is directly shaped with the circuit board. Because the reserved position of the antenna area is insufficient, to reduce the use area of the antenna through serpentine wiring.

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Q: 2. What are the disadvantages of on-board antenna?

A: Small size antenna may cause the antenna receiving effect is not as good as the external antenna. The onboard antenna has high environmental requirements. Therefore, keep a certain distance between the antenna and the metal as far as possible.

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Q: 3. Is onboard preferred?

A: It mainly depends on whether the area reserved by the antenna can meet the performance requirements of the onboard antenna during the product design, and if it does not meet the performance requirements, then pulled out the antenna.

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Q: 4. Where should I put the TV antenna?

A: The TV antenna is generally placed behind the TV backplane, the shrapnel antenna and FPC/PCB antenna are generally selected, the shrapnel antenna is generally affixed to the metal backplane, and the FPC/PCB is affixed to the plastic parts of the backplane.

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Q: If used for a switch, which antenna is better?

A: It is recommended that the antenna engineer to evaluate the antenna performance in the early stage , if the product space is large, it is recommended to pull out the antenna, choose the FPC/PCB material antenna, low cost, simple assembly.

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Q: 6. What are the application scenarios of onboard antenna and patch antenna?

A: Onboard antenna is generally suitable for module, headroom environment is sufficient, the main application and smart home and other products.

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Q: 7. How far can this antenna receive?

A: How far the antenna signal can be transmitted depends not only on the performance of the antenna itself, but also on the intensity of the transmitted power at the chip end.

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Q: 8. Does the internal antenna work the same as the external antenna?

A: Different, the internal antenna is closer to the internal environment of the whole machine, the degree of environmental interference is greater, the external antenna is generally placed on the shell of the whole machine, the effect of antenna radiation will be better.

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Q: 9. Bluetooth module also belongs to the antenna class?

A: No, the module belongs to the RF device of a system.

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Q: 10. What is the common anti-jamming method of Ai-Thinker antenna?

A: Interference in the industry is generally divided into radiation interference and conducted interference, the antenna generally does not have the ability to resist interference, the antenna location is generally placed away from the interference source environment.

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Q: 11. What is the use of wavelength?

A: Wavelength is the electrical length corresponding to the frequency and is the main parameter for designing the antenna.

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Q: 12. Does the GPS module also include antenna?

A: No, the antenna is separate.

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Q: 13. What are the propagation characteristics of different frequency bands?

A: Propagation characteristics depend on the product category.

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Q: 14. Which antenna has the longest communication distance?

A: Antenna transmission distance depends on chip transmitting power and antenna gain.

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Q: 15. What should we pay attention to in the design of silk screen antenna?

A: Pay attention to the clearance environment in the antenna area, and try to stay away from metal.

Q: 16. What is the difference between onboard antenna and ceramic patch antenna?

A: The difference between the two is the frequency band used and the material of the antenna.

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Q: 17. How to understand antenna gain?

A: The size of the antenna gain determines the distance the signal can travel.

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Q: 18.how to ensure that there is no interference between the antenna and other circuit components?

A: Install antennas far away from interference sources.

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Q: 19. What is directional antenna and non-directional antennas? What's the difference?

A: Directional antennas are generally class directional antennas and base station antennas, and there are more types of non-directional antennas, which are generally divided into linearly polarized antennas, circularly polarized antennas, and elliptically polarized antennas.

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Q: 20. How does the flexible structure affect the radiation characteristics of the antenna?

A: It is not recommended to mount antennas in flexible structures, and the antennas should be placed in the position of fixed structures as far as possible. Changes in flexible structures will affect the performance of the antennas.

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Q: 21. Does the antenna mismatch affect the product?

A: Antenna mismatching will affect the radiation of transmitted power, and mismatching will cause energy reflection.

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Q: 22. How does the manufacturing material of the shrapnel antenna affect its performance?

A: Shrapnel antennas are generally made of stainless steel, and metal materials do not affect antenna radiation.

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Q: 23.What are the factors that affect the antenna signal?

A: Chip transmit power, metal environment ratio of the whole machine, antenna matching degree.

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Q: 24. How to improve the antenna signal quality in the environment of radio interference,?

A: Try to stay away from radio interference.

Q: 25. How to know whether the antenna matches?

A: Professional equipment such as a network analyzer can be used to verify that the antenna matches.

Q: 26. How does the length of the rod antenna relate to its operating frequency??

A: The lower the antenna frequency, the longer the physical length of the rod antenna.

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Q: 27, How to deal with signal changes in high-speed moving environments, such as high-speed trains?

A: Generally, there will be a base station signal near the high-speed rail line, which can generally meet the general use needs, if you enter the tunnel, the signal may be shielded, and this can only be used after the tunnel.

Q: 28. What should you pay attention to the antenna drawn directly on the PCB??

A: Pay attention to the layout of the antenna area and the choice of antenna form, generally choose PIFA antenna and monopole antenna.

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Q: 29. How to wire PCB antenna?

A: Generally, half-wave dipole antennas are selected, and appropriate wiring is selected according to the size of the PCB.

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Q: 30. How does weather affect the performance of external antennas?

A: The weather has an effect on the antenna, which affects the radiation of electromagnetic waves.

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Q: 31. Which antenna works better, PCB or external antenna?

A: The antenna structure or antenna form is not the same, which does not affect the antenna effect, depending on the match between the antenna and the installed environment.

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Q: 32. Does the antenna have power?

A: The antenna is a passive device, no power, the antenna is only responsible for radiating energy.

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Q: 33.If don't have enough power, will the wrong antenna burn?

A: No, the current inside the consumer antenna is very small.

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Q: 34. Which kind of communication distance does the same module use?

A: The higher the gain of the antenna, the further the signal is transmitted.

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Q: 35. Is onboard interference a big influence?

A: The interference size depends on whether the mainboard has interference sources.

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Q: 36. Does the extension length of the coaxial cable of the antenna affect the standing wave?

A: There is a loss of coaxial line, the longer the length, the greater the energy loss.

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Q: 37. What are the biggest challenges in antenna design?

A: Overall environment.

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Q: 38. How to solve the problem of mutual interference between antennas?

A: There are several general solutions to the interference between the antennas, the farther the distance between the antennas, the different polarization modes of the antennas can also be solved, and the dislocation of the antennas.

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Q: 39. What is the communication distance of onboard antenna? How does it go through the wall?

A: The communication distance of the onboard antenna depends on the environment of the whole machine, the general BLE antenna transmission distance is about 100 meters, and it can generally pass through 2 walls.

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Q: 40. How to evaluate the efficiency and performance of the antenna?

A: Antenna performance looks at two parts, passive performance looks at gain efficiency /S11 parameters, active performance looks at power and sensitivity.

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Q: 41. How to avoid aircraft model interference when use 5.8G antenna?

A: Consider using an omnidirectional antenna, then adjust the appropriate channel to try.

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Q: 42. Does the onboard antenna have requirements for the thick plate?

A: No requirements, depending on motherboard thickness.

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Q: 43. What’s the main application scenarios of Ai-Thinker antenna?

A: It can be applied to the field of Internet of things, such as smart home, intelligent transportation, intelligent logistics, etc.

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Q: 44. What are the simulation tools used in antenna engineering?

A: HFSS/CST, etc

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Q: 45. Does the module have the test function of antenna standing wave ratio?

A: The module antenna will test the S11 parameters.

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Q: 46. Can Ai-Thinker support a full set of antenna customization?

A: Support, from early evaluation to the whole machine commissioning test.

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Q: 47. The better the standing wave, the higher the efficiency?

A: If standing waves are good, antenna efficiency is not necessarily good, but if standing waves are bad, antenna efficiency is certainly bad.

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Q: 48. What kind of amplification antenna is used for cell phone signal?

A: Generally, there is a power amplifier on the RF motherboard link.

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Q: 49. Does plastic wrap have a big impact on onboard antennas?

A: Different plastic materials have an impact on antenna performance, and the size of the impact needs to be verified by actual testing.

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Q: 50.What is the difference between millimeter wave antenna and traditional antenna?

A: Millimeter wave application scenarios are different, and the antenna design generally uses patch antennas.

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Q: 51.What is the power consumption of the antenna?

A: The loss of the antenna depends on the performance of the antenna.

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Q: 52. how to achieve multi-frequency shared antenna?

A: A multi-band antenna can be made by adding different lengths of knuckles.

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Q: 53. What range of metal shell will affect the power of the antenna?

A: The metal shell should be as small as possible, and the antenna should be as far away from the metal as possible if it cannot be changed.

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Q: 54. Does the shape of the antenna affect the efficiency?

A: Antenna design has little influence on antenna efficiency, but antenna matching has great influence on antenna efficiency.

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Q: 55.Is the transmission distance of Bluetooth subject to antenna interference in other environments?

A: Bluetooth transmission distance can indeed be affected by antenna interference. This is mainly because the electromagnetic waves generated by other devices and signal sources may block the receiver of the Bluetooth device, thereby affecting its normal reception and transmission of data.

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Q: 56. What type of antenna do you choose for low-power devices?

A: Low power devices When selecting an antenna, you need to consider factors such as device size, cost, and performance. For short-range wireless devices, common antenna types are PCB antennas, chip antennas, and whip antennas.

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Q: 57. How does the antenna deal with the problem of multipath propagation and signal attenuation?

A: Multipath propagation strategy: spatial diversity technology, OFDM technology

The common solutions to the problem of signal attenuation are: increasing transmission power and using high-gain antennas.

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Q: 58.How do antennas between multiple smart home devices avoid interfering with each other?

A: The available bandwidth can be increased, and improving antenna isolation by using multiple antennas and employing intelligent algorithms to calculate the best antenna combination is another effective approach.

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Q: 59. If the omnidirectional antenna is half blocked, can it be regarded as a directional antenna?

A: If you block the omnidirectional antenna in half, it will still send signals in all directions, so it cannot be said that it has become a directional antenna. In fact, blocking the omnidirectional antenna does not change its basic property, that is, the characteristic of 360° uniform radiation on the horizontal pattern.